WATCH: Limerick 4-year-old learns a “bad word” and can’t stop singing it

Anyone with kids knows that once you've told them not to say a word, there's a 50% chance they're going to come up with a song where the only lyrics are the word you've told them not to say.

That's exactly what young Tiarnán from Limerick did when he first heard the word "vagina." Luckily for the rest of us, one of his siblings captured Tiarnán's performance on video and stuck it on YouTube. In the video, we can see Tiarnán singing "vagina" to his own reflection in the microwave... It's hard to make out pretty much any of the other words but... the important one is clear. https://www.youtube.com/watch?v=YmaNZZZ3iBE They'll be waiting a while for him to get this out of his system, that's for sure.